An immunochemical assay device for determining the presence of NT-proBNP alone or conjunctively with Cardiac Troponin I comprising a base member, an array disposed on the base member, and at least one assay indicia zone. The array comprises (i) a reservoir pad to receive sample liquid, (ii) a wicking membrane, and (iii) at least one filter zone interposed between the wicking membrane and the reservoir pad. The filter zone being operable to permit passage of any specific immunocomplex to the wicking membrane while impeding passage of larger components.